Experimental cross section of Sm-144(alpha, gamma)Gd-148 and implications for the p-process

The cross section of the Sm-144(alpha, gamma) Gd-148 reaction has been measured at bombarding energies in the 10.5-13.4 MeV range using an activation method based on the off-line alpha-activity measurement of the Gd-148 residual nucleus. The long measuring time of the alpha-decay has required the use of etched track detectors. The resulting cross sections and astrophysical S-factors are compared to new statistical model calculations. The measured data at low energies reflect the strong energy dependence of the optical potential which is found to affect significantly our predictions of the alpha-capture rate.